The type Permian; its classification and correlation
The type Permian; its classification and correlation
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二叠纪类型；
DOI：
10.1306/3d9331a4-16b1-11d7-8645000102c1865d
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发表时间：
1940
期刊：
影响因子：
3.5
通讯作者：
C. O. Dunbar
中科院分区：
文献类型：
--
作者：
C. O. Dunbar
通过对乌拉尔西部广大盆地地层的回顾，揭示了二叠系可划分为5个系的关系。这些与中国南部和美国西南部的二叠纪矿床相关。通常被认为是上石炭统的俄罗斯台地灰岩，与通常被认为是二叠纪的阿廷斯克碎屑相当。阿廷斯克的下边界不是一个固定的地层层位，而是重叠相之间的接触。虽然从上石炭世开始到二叠纪，在该盆地的沉积物中没有发现明显的断裂，但广泛的观点表明，地槽在很大范围内的快速下沉始于假schwagerina动物群的入侵。乌拉利地槽快速演化的开始与美洲沃尔夫坎普系列底部的区域性断裂和东方同一水平面的深刻的区域性断裂有关。因此，二叠系最自然的下限在假schwagerina带的底部，即苏联的Sakmarian底部、美国的Wolfcamp底部、中国南方的船山底部和阿尔卑斯山脉的Schwagerinakalk底部。
A review of the stratigraphy of the vast basin west of the Urals shows the relation of the five series into which the type Permian is divisible. These are correlated with the Permian deposits of South China and southwestern United States. The limestones of the Russian platform, commonly considered Upper Carboniferous, are shown to be equivalent to the Artinsk detritals, which are generally recognized as Permian. The lower boundary of the Artinsk is shown to be not a constant stratigraphic horizon but the contact between overlapping facies. Although no widely recognizable break has been demonstrated in the deposits of this basin from the beginning of the Upper Carboniferous into Permian time, a broad view shows that the rapid subsidence of the geosyncline over a very great area began with the incursion of the Pseudoschwagerina fauna. This beginning of a rapid evolution in the Uralian geosyncline is correlated with the regional hiatus at the base of the Wolfcamp series in America and a profound and regional break at the same horizon in the Orient. It is concluded, therefore, that the most natural lower limit of the Permian system is at the base of the Pseudoschwagerina zone, that is, at the base of the Sakmarian in the U.S.S.R., of the Wolfcamp in America, of the Chuanshan in South China, and of the Schwagerinakalk in the Carnic Alps.